1. Field of the Invention
This invention relates generally to microwave switches and more particularly to a multi-throw microwave stripline switch utilizing PIN diodes.
2. Description of the Prior Art
There are various microwave multi-throw switches in the prior art. Such prior art switches include those utilizing striplines with beam lead PIN diodes extending across stripline segments. There are other structures utilizing PIN diodes mounted in a horizontal position with the conductive layer of the diode superimposed on a stripline and the junction lead extending across the gap between striplines to another stripline.
In microwave multi-throw switches, performance is highly dependent upon isolation losses, voltage standing wave ratios and insertion losses. In the known prior art structures the beam lead diodes provide a structure of significant improved performance over that of the conventional PIN diodes in these three operating characteristics. However, the cost to manufacture beam lead PIN diodes is substantially greater than that of the conventional PIN diode.
As a consequence, when operating in the two gigaHertz to eighteen gigaHertz frequency range either beam lead diodes are used exclusively or they are used in combination with a conventional PIN diode.